/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.06.01 02:42:29
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

int main() {
    int n, m;
    cin >> n >> m;
    if (m == 0) {
        cout << 0 << endl;
        return 0;
    }
    constexpr int INF = 1e9 + 6;
    vector< vector< vector< int > > > dp(m + 1, vector< vector< int > >(2, vector< int >(2, -INF)));
    dp[0][0][0] = 0;
    auto dp2 = dp;
    vector<int> w(n);
    for (int i = 0; i < n; i++) {
        cin >> w[i];
    }
    for (int i = 0; i < n; i++) {
        if (i == 0) {
            for (int j = 0; j <= m; j++) {
                dp2[j][0][0] = max(dp[j][0][0], dp[j][1][0]);
                if (j - 1 >= 0) dp2[j][1][1] = max(dp[j - 1][0][0], dp[j - 1][1][0]);
            }
        } else if (i == n - 1) {
            for (int j = 0; j <= m; j++) {
                dp2[j][0][0] = max(dp[j][0][0], dp[j][1][0]);
                dp2[j][0][1] = max(dp[j][0][1], dp[j][1][1]);
                if (j - 1 >= 0) dp2[j][1][0] = max(dp[j - 1][0][0], dp[j - 1][1][0] + w[i-1]);
                if (j - 1 >= 0) dp2[j][1][1] = max(dp[j - 1][0][1] + w[i], dp[j - 1][1][1] + w[i-1] + w[i]);
            }
        } else {
            for (int j = 0; j <= m; j++) {
                dp2[j][0][0] = max(dp[j][0][0], dp[j][1][0]);
                dp2[j][0][1] = max(dp[j][0][1], dp[j][1][1]);
                if (j - 1 >= 0) dp2[j][1][0] = max(dp[j - 1][0][0], dp[j - 1][1][0] + w[i-1]);
                if (j - 1 >= 0) dp2[j][1][1] = max(dp[j - 1][0][1], dp[j - 1][1][1] + w[i-1]);
            }
        }
        dp = dp2;
        dp2.assign(m + 1, vector< vector< int > >(2, vector< int >(2, -INF)));
    }
    cout << max({dp[m][0][0],dp[m][0][1],dp[m][1][0],dp[m][1][1]}) << endl;
    return 0;
}